The idea of welding together a stainless steel tube with ½ inch ports on it—one tube portion for fill, and another tube portion for drain—every time one needs to build a manifold is time consuming and costly. Using strong polyethylene doughnut pieces, whereby each one is provided with a side access port, to quickly and easily build a modular manifold would be a much better solution. Most known modular setups lack side access to build manifolds, and, in fact are designed for an entirely different purpose, namely to connect PVC and/or metal pipes, not to create manifolds. The need arises, therefore, for a modular manifold that can be easily and securely assembled and that can provide multiple side ports by increasing or reducing the number of doughnut pieces being used, as needed.